Robotics is an active area of research, and many different types of robotic vehicles have been developed for various tasks. For example, unmanned aerial vehicles have been quite successful in military aerial reconnaissance. Recently, there has been much advancement in the field of unmanned ground vehicles. These unmanned ground vehicles vary widely and are adapted to traverse a wide variety of terrain, including for example, loose and shifting materials, obstacles, vegetation, limited width or height openings, steps, and the like.
A vehicle optimized for operation in one environment may perform poorly in other environments. For example, large vehicles can handle some obstacles better, including for example steps, drops, gaps, and the like. On the other hand, large vehicles cannot easily negotiate narrow passages or crawl inside pipes, and are more easily deterred by vegetation. Large vehicles also tend to be more readily spotted, and thus are less desirable for discrete surveillance applications. In contrast, while small vehicles are more discrete and can negotiate certain paths better than larger vehicles, surmounting certain obstacles can be a greater navigational challenge.
A variety of mobility configurations within robotic vehicles have been adapted to traverse difficult terrain. These options include legs, wheels, and tracks. Legged robots can be agile, but such systems can require complex control mechanisms to move and achieve stability. Wheeled vehicles can provide high mobility, but can provide limited traction and can require more overall robot width in order to achieve stability.
Tracked vehicles are known and have traditionally been configured in a tank-like configuration. While tracked vehicles can provide a high degree of stability in some environments, tracked vehicles typically provide limited maneuverability when employed on small vehicles. Furthermore, known tracked vehicles are unable to accommodate a wide variety of obstacles, particularly when the terrain is narrow and the paths are tortuous and winding.
A further limitation of ground vehicles is that of negotiating or manipulating complex obstacles. Manipulation of complex obstacles such as twisting a doorknob, or climbing the rungs of a ladder, climbing fences (e.g., chain link fences, etc.) become insurmountable to a simple legged robot or a wheeled or tracked robot. A reconnaissance drone operating on the ground would be unable to enter a closed door, climb a ladder, climb a fence or enter a pass code on a keypad. Known unmanned ground vehicles are currently unable to perform a wide variety of tasks, particularly when the task requires controlled manipulation of an object or controlled force balancing in multiple directions.